PURPOSE: To evaluate the effectiveness on reducing anxiety of a diaphragmatic breathing relaxation (DBR) training program.DESIGN AND METHODS: This experimental, pre-test-post-test randomized controlled trial with repeated measures collected data using the Beck Anxiety Inventory and biofeedback tests for skin conductivity, peripheral blood flow, heart rate, and breathing rate. FINDINGS: The experimental group achieved significant reductions in Beck Anxiety Inventory scores (p < .05), peripheral temperature (p = .026), heart rate (p = .005), and breathing rate (p = .004) over the 8-week training period. The experimental group further achieved a significant reduction in breathing rate (p < .001). PRACTICE IMPLICATIONS: The findings provide guidance for providing quality care that effectively reduces the anxiety level of care recipients in clinical and community settings.